Which of the following medications does the nurse identify as a calcium channel blocker used to treat tachycardia and manage heart rate?

Choice A rationale:

Dopamine was once considered a first-line vasopressor for cardiogenic shock. However, recent studies have shown that it is associated with increased mortality compared to norepinephrine.

Dopamine has dose-dependent effects on dopamine receptors, beta receptors, and alpha receptors. At low doses (1-5 mcg/kg/min), it primarily stimulates dopamine receptors, leading to renal vasodilation and increased urine output. At moderate doses (5-10 mcg/kg/min), it stimulates beta receptors, resulting in increased heart rate and contractility. At high doses (>10 mcg/kg/min), it stimulates alpha receptors, causing vasoconstriction.

The main concern with dopamine is its potential to cause arrhythmias, particularly at higher doses. This is due to its effects on beta receptors, which can increase heart rate and myocardial oxygen demand.

Additionally, dopamine can cause tachyphylaxis, meaning that its effects can diminish over time, requiring higher doses to achieve the same effect.

Choice B rationale:

Norepinephrine is a potent alpha-adrenergic agonist that causes vasoconstriction, leading to an increase in blood pressure. It has minimal effects on beta receptors, so it is less likely to cause tachycardia and arrhythmias compared to dopamine.

Norepinephrine also has some inotropic effects, meaning that it can increase the strength of contraction of the heart muscle.

Studies have shown that norepinephrine is associated with improved survival rates in patients with cardiogenic shock compared to dopamine.

It is generally well-tolerated, with the most common side effects being hypertension and peripheral vasoconstriction.

Choice C rationale:

Epinephrine is a potent alpha- and beta-adrenergic agonist that causes vasoconstriction, increased heart rate, and increased contractility.

It is typically used as a second-line agent in cardiogenic shock, after norepinephrine has failed to achieve adequate blood pressure.

Epinephrine can cause significant tachycardia and arrhythmias, so it should be used with caution in patients with underlying heart disease.

Choice D rationale:

Vasopressin is a hormone that causes vasoconstriction by acting on V1 receptors in vascular smooth muscle. It is sometimes used as an adjunct to norepinephrine in patients with refractory cardiogenic shock.

Vasopressin has the potential to cause coronary vasoconstriction, so it should be used with caution in patients with coronary artery disease.

Choice A rationale:

It is not recommended to take levothyroxine with food as it can interfere with its absorption.

Food, particularly those containing calcium or iron, can bind to levothyroxine in the gastrointestinal tract, reducing the amount of medication that is absorbed into the bloodstream.

This can lead to decreased effectiveness of the medication.

It's generally advised to take levothyroxine on an empty stomach, at least 30-60 minutes before breakfast, to ensure optimal absorption.

Choice B rationale:

Taking levothyroxine first thing in the morning, on an empty stomach, is the most effective way to ensure its absorption and consistent hormone levels throughout the day.

This aligns with the body's natural rhythm of thyroid hormone production, which typically peaks in the morning hours.

Taking the medication consistently at the same time each day helps maintain stable thyroid hormone levels, which is crucial for managing hypothyroidism effectively.

Choice C rationale:

Relief of symptoms with levothyroxine therapy often takes several weeks, not just one week.

It takes time for the body to adjust to the medication and for thyroid hormone levels to reach a therapeutic range.

Patients should be counseled to have patience and continue taking the medication as prescribed, even if they don't experience immediate symptom relief.

They should also be monitored regularly by their healthcare provider to assess their response to treatment and make any necessary adjustments to the dosage.

Choice D rationale:

Doubling the dose of levothyroxine without consulting a healthcare provider is dangerous and can lead to serious health consequences.

Overdosing on levothyroxine can cause hyperthyroidism, which can manifest as rapid heart rate, anxiety, tremors, weight loss, and other health problems.

It's essential to follow the prescribed dosage and not make any changes without the guidance of a healthcare professional.